Programmable logic devices (PLDs) are becoming increasingly complex and powerful and capable of implementing a wide range of functionality. The power of PLDs in combination with ease of configuration and reconfiguration are factors in the increasing popularity of these devices.
Various security and control issues are increasing in importance as designs become increasingly complex. The costs associated with developing complex designs are great, making these designs targets for theft and infringement. The configuration data, which implements a design and may be used to configure a PLD, may include parts that are derived from licensed designs, as well parts developed by a user at significant expense. A PLD is easily configurable with configuration data. Likewise, the configuration data may be easily read back from the device and deployed on other similar devices. Preventing unauthorized use and exposing piracy of a design may be difficult because the configuration data may be easily copied. Confirming the unauthorized use of a design in a suspected copy may also be difficult.
In addition to configuration data, other information of interest in a complex design may include revision control and design-identifying information. Associating revision and design description information with the configuration data may be desirable. However, in certain situations making this information apparent to an unauthorized observer may be undesirable.
The present invention may address one or more of the above issues.